Method of manufacturing shoe shank stiffeners



Oct. 27, 1931. R B. BARTELS 1,829,496

MEFHOD OF MANUFACTURING SHOE SHANK STIFFENERS Filed May 8. 1929 2Sheets-Sheet l ,5 f/ 1/4 J7 w 0st. 27, 1931. R, BARTELS 1,829,496

METHOD OF MANUFACTURING SHOE SHANK STIFFENERS Filed May 8. 1929 2Sheets-Sheet 2 Patented Oct. 27, 1931 PATENT OFFICE REINHARD B. BARTELS,OF

MELROSE, MASSACHUSETTS METHOD OF MANUFACTURING SHOE SHANK STIFFENERSApplication filed May 8,

Heretofore it has been customary to make metallic shank stiffeners forshoes, when the stiffeners are provided with integral attaching prongs,by cutL-ing them from strip stock, of the width of the stiffeners. Theattaching prongs, more particularly those of substantial length whichmust be bent to securely clinch when they are driven into the solemember as at the forward ends of stiffeners for welt or McKay shoes, arecut lengthwise of the strip so that they bend crosswise of the grain ofthe metal which is produced when it is rolled into sheet form. Thenarrow width stock is, however, more expensive weight for weight thanwider strip stock, since more operations are required to reduce it tonarrow condition. If, however, it be attempted to cut this same form ofstiffener widthwise from a relatively wide strip, not only is thereconsiderable waste at the edge or edges where the prongs are formed, butthese prongs extend across the grain of the metal and are much less ableto withstand bending in the clinching operation without breaking. If, inorder to overcome this liabilty to breakage of the prongs a relativelysoft metal is used, this is considerably more expensive than the hardermetal, as it must be subjected to annealing, and further, a greaterweight of such softer metal is necessary for the same degree ofstiffness of the stiffener. If these relatively long pron 's are cutfrom the body of the stiffener widt wise so that they may be bent acrossthe metal grain, so much of the metal is cut away that I the stiffeneris liable to break off at the prongs. These drawbacks to the use of widestock have therefore heretofore prevented its use for the manufacture ofintegral pronged stilfeners. Y

This invention has for an object the production of a pronged stiffenerwhich is particularly suitable for cutting wid'hwise from wide stripstock and wherein the long prongs bend across the grain when beingclinched,

but which are so constructed that the stiffener isuot unduly weakenedwhere the prongs are formed. To this end, each prong is cut from thestock of two adjacent side by side stiffener portions of the strip sothat each prong may 1929. Serial No. 361,390.

be of a length equal to one-half the width of the stiffener and yetleave one-half of the width of the stiffener at the prongs uncut. Notonl does this construction make possible the cuttlng of the stiffenerswidthwise, but in the case of a stiffener provided with a centrallongitudinal stiffening rib formed by a lateral bending of thestifl'ener, it makes possible the successful use of stock harder andless expensive than heretofore required for lengthwise cut stiffeners,since in the lengthwise cut stiffeners the rib is formed by bending themetal with the grain, which is likely to cause cracking if the harderstock is used, while in the cross cut stiffeners this rib is formed bybending across the grain.

For a more complete understanding of this invention, reference may behad to the accompanying drawings in which Figure l is a side elevationof a finished stiffener.

Figure 2 is a cross section on line 22 of Figure 1.

Figure 3 is a perspective of the wide sheet showing successive stages ofthe cutting and forming of stiffeners therefrom.

Figure 4 is a fragmentary plan of one portion of a strip showing onearrangement of the prongs.

Figure 5 is a detail section on line 55 of Figure 4.

Figure 6 is a fragmentary plan showing a different arrangement of theprongs.

Figures 7 and 8 are detail sections on lines 7 -7 and 8-8, respectively,of Figure 5.

Figure 9 is a view partly in elevation and partly in section of a diefor cutting and forming the strip as shown in Figure 3.

Figures 10 to 13 are detail sections on the correspondingly markedsection lines of Figure 9.

Referring to these drawings, at 1 is indicated a strip of sheet metalfrom which the stiffeners are to be cut, this strip being of a widthsubstantially equal to the length of the desired stiffeners. This stripis passed between the die members 2 and 3 shown in Fig ures 9 to 13. Thedie member 3 is provided with supporting ledges 4 and 5 along oppositesides and is also provided with upwardly spring pressed stripper members6 and 7 which act to lift the strip from contact with the portions t and5 when the upper die member 2 is elevated. The die as shown is intendedto perform the same operations on two stiffener blank portionssimultaneously. The first operation performed consists in formingcertain of ,the attaching prongs. For this purpose the upper die member2 is provided at one end with cutting and bending elements 10, which onthe descent oi-the upper die member 2 cut and strike tromone edgeportion of the sheet metal strip 1 downwardly extending prongs 11.Adjacent tothe opposite margin of the sheet 1 other attaching means forthe 'sultener m'ayalso be: formed at the same time;

'Qne form of such attaching means comprises the relatively short prongs12 which are g this purpose.

- secondset ofaprongs. arelstruclg'the stripcmay 1lee-partially;cut'laterally,'as by means ofthe" st-r uclr from the sheet1 by means of the upper die portion 13 (seeFigures 3, and 1-0) At the:neXt station the matetriallapping atone side of each of theportione'from which the'prongs llwere struck is struck down in theopposite direction, thus to form prongs15, the upper die member 2having-cutting elements 16 for At the, same time. that the slitszl'?formed by thecutters 18 of 'theLupper, die member, leaving uncutmarginal portions 'These slits 17 aremade oppositeto the centralportions of theside by side lapping lengths ofqmaterial from which theprongs 11 and aregform'ed and'defiine op- 1 pesite edges of thestripsections for .the in 1; 1or;the: stitfeners 1s 1 not required to be :sosedividual stitleners being formed. 7

- At thenextistationzthe'.partiallycut strip sections are molded to forma central longi- 'tudinallyextending stiffening rib as at 18, :the upperdie member 2'bein g-provided with molding elements 20 forthispurpose.These ribs may bemade'either'side up. Itisthen desirable tohaveone ormore vacant stations after which the partially severed str-ipsnaremolded to their desired a longitudinal curvatures, the upper die member2 being provided with molding members 21 for this purpose. A spacebetweenithis longitudinal molding andthe-operations previously performed1s desirable, since this longitudinal molding i'causes adrawing inof=the edges ofthe strip '1: and it is desirable that this drawing in beaccomplished without affecting '7 in any way the die portions forperforming the previous operations. Afterthe ,partially severed sectionshave thus been molded to the'desired longitudinal curvature they arecompletely severed toform stiflenersasby means otthe V rtending inparallelrrelation. VVh-en thestif cutters 25 carried by the upperdiememher;

erance 3O between the portions struck out exf eners are so-cutithepoints ofthe prongs are 1 o'fi'set from each other lengthwise of thestif TTheprongs 11 and 15 can be cut as: shown ingFigures 4 orr5, all;the diagonal lines of sevcaseboth prongs ofeach-stifi'enercome opcpos-ite to :each anther vlen gthwise v or the stiffener, but those ofone stiffener have their diagonal edges facing outwardly toward theadjacent-endofthc "stiff-eners as shown at in Figure 7 and'thestiffeners cut from the strip portions next adj acent thereto have thediagonal sidesof the prongs inwardly facing as at 33'i1rFigure8.Inbothcases, however,

it will notedthat one-halfthe length of 'eaoht'prongis cut from'thestock of. the next adjacentstrip portion thereto, so. that c theseprongs maybe made eachcof allength of onehalfthewvidth of the stripportion and yet between-the opposed-prongs of each strip portion thereis left an uncut space equal '111 .widtlnto thelength of each of thelong*z-rongs and, so equali-n lengthto one-half. the

width of the completed stiffener. Moreover,

:ElS t-h31fil'fllll: of the metalxrunsilengthwise of the -;strip 1, theline I of bending of 1 each of these prongs is-it-ransverse' to theline:of;this

; grain so a that the prongs can .be bent, when the stifienerrisfixed totheisole member by clinching-the prongs oven without danger offln-eakage. shouidibe :placed :at .tllQfOI'WlIid; endsi'of. thestiileners which --are to be" used i for welt or These :relatively longI prongs McKayshoes. The'rear endfastening means -cure,2 since thisportion comes over the heel and is securely fixed by the neighboringportions' of the 1 shoe, A relatively "short prong 'Whl'Ch:ltiSI10tiH6CGSSlTY-t0 clinch inthe material is therefore all: that isnecessary. These short prongs may be formedi-nvarious ways,

therefore, Figures Grand? showing a different c :The ElOWQI' :die;member 13 :is, ;of course,

1formedcomplementally .to'the upper die mem- ,ibe r2 and isprovided withsuitable grooves 40 f WllJlllIl which the pron-gs be :bent by the.za'et-ion of :the upper :(118 :members 110 and 1 16' and within whichthey may be positioned when the strip material is carried downwardlyagainst'thepressureof the strippers 6 and 7 atzeachtlownward-strokeofthe die member .1. At:=the opposite-side'ofathe"die'inember 3 imayalso be :iiormedsuitable depressions or :grooves- -shape'd to "receivethe fastening .pre-n'gsstruck fronithe opp ositec edge portion otthesheet. 'Cl he iowerdiemember 3 may naiso be provided}with inwardly projeoting marginal upper walls 45 to limit the upward :"movementl'ofithe.stripas iraise'd' by the strippers when the upper die member 2 is in itsraised position as shown in Figure 9. The lower die member may also beprovided with vertical guideways 50 to guide the motion of the upper diemember 2.

Each of the completed stiffener members, it will be seen, comprises alaterally extending strip section 51 cut from the relatively wide strip1, and has a centrally depressed reinforcing rib 18, a pair of spacedrelatively long integral attaching prongs l1 and 15 at one end bent fromportions of greater width than the body portion of the stiffener andrelatively short integral attaching prongs 12 adjacent to its oppositeend. If it were attempted to strike the long prongs from the material ofthe width of one indi-' vidual strip portion there would be insufficientmaterial to make these prongs of the necessary length. As the stripmaterial 1 as commercially made varies slightly in width, it should befed into the die pressed against the left hand edge as viewed in Figures10 to 13, so that the prongs 11 and 15 may all be of full size. Theprongs at the opposite end of the stiffener being formed slightlyinwardly from the end of the stiffener and inwardly from the edge of thestrip 1 are therefore not affected by the slight commercial variationsin width of the strip 1.

From the description of certain embodiments of the stiffener, togetherwith a method and means by which such stiileners may be formed, itshould be evident to those skilled in the art that various changes andmodifications might be made therein without departing from the spirit orscope of this invention as defined by the appended claims.

I claim:

1. The step in the manufacture of shoe shank st-iffeners with integralprongs, said stifieners comprising strip portions severed widthwise froma strip of a width substantially equal to the length of the stiffeners,which comprises striking each of said prongs from stock of its stripportion and from that next adjacent thereto, the material of the prongsfor adjacent strip portions extending past each other in side by sidelapping relation before the prongs are struck.

2. The method of making shoe shank stiffeners, which comprises strikingintegral at taching prongs from side by side lapping oppositelyextending lengthwise portions at intervals along the length of a stripof a width substantially equal to the length of the stiffener, andsevering the strip laterally into stifi'ener strips along linessubstantially centrally of said lapping portions.

3. The method of making shoe shank stiifeners, which comprises strikingintegral attaching prongs from side by side lapping oppositely extendinglengthwise portions at intervals and at the edge portion of a strip of awidth substantially equal to the length of the stifi'eners, severing thestrip laterally between uncut margins along lines substantiallycentrally of said lapping portions, molding each partly severed sectionto the desired lateral and longitudinal curvatures of the stiffener, andthen completing the severing of said sections from each other.

4. The method of making shoe shank stifleners, which comprises strikingintegral at taching prongs from side by side lapping oppositelyextending lengthwise portions at intervals and at the edge portion of astrip of a width substantially equal to the length of the stifieners,partially severing the strip laterally along lines substantiallycentrally of said lapping portions, forming a central longitudinallyextending rib in each of said partially severed sections, molding eachof said sections to a longitudinal curvature, and then completing thesevering of said sections from each other to form stiiieners.

In tesimony whereof I have affixed my signature.

REINHARD B. BARTELS.

